Automatic plate changing mechanism for printing press



AUTOMATIC PLATE CHANGING MECHANISM FOR PRINTING PRESS Filed Dec, 22, 1960 J. B. BRUNT Dec. 3, 1963 4 Sheets-Sheet l 0 0 y w 0 l M 2 0v 0 0 fi 4 m 0 p fi 7w 9 m I I m 3 x0 Q fi I \O "R m: illr a 1m .1 \W WW g m n w 1 m 1 1 mQ i 3 H I W r u I 4 I. l 0 6 2 7 6 z .n 5 m G fi I HA0 III I 9/0 2 '4 a 1 a 4 a 9 W x 2 w U R R m5 M J J ORNEY Dec. 3, 1963 J. B. BRUNT 3,112,696

AUTOMATIC PLATE CHANGING MECHANISM FOR PRINTING PRESS Filed Dec. 22, 1960 4 Sheets-Sheet 2 INVENTOR. JOHN B. BRUNT Dec. 3, 1.963 J. B. BRUNT 3,112,695

AUTOMATIC PLATE CHANGING MECHANISM FOR PRINTING PRESS Filed Dec. 22, 1960 4 Sheets-Sheet 3 I. 42 !'l '1 Q I H A QI I L INVENTOR. Jam/B. BRUNT Dec. 3, 1963 J. B. BRUNT 3,112,696

AUTOMATIC PLATE CHANGING MECHANISM FOR PRINTING PRESS Filed Dec. 22, 1960 4 Sheets-Sheet 4 gmnnnnr IN V EN TOR.

] JOHN B. BRUNT United States Patent Ofiice Patented Dec. 3., 1963 3,1125% AUTOMATEC PLATE SEAT GE S MEQHANESM FQR PRlNf'lNG PRESS Ilohn l3. Brunt, Newark, NJ assignor, by mesne assign= ments, to Faireliild Camera and instrument Corporation, a corporation of Delaware Dec. 22, 1%60, Ser. No. 77,740 9 Claims. (Cl. 1912l7) This invention relates to control means for printing presses employed in short run operations, such as the press which is the subject of US. Patent 2,759,416, and more particularly, to means for controlling the presentation of printing plates and their subsequent attachment to the printing cylinder of such a machine.

In short run printing operations, generally only a small number of printed copies are reproduced from each printing plate, which means that during the course of a day it is necessary to change printing plates quite frequently. In order to minimize the non-productive time during which plates are being changed it has been found to be advantageous to efiect the change of plates automatically without the necessity of arresting the rotation of the printing cylinder.

The method of changing printing plates employed heretofore consisted of placing the control handle in the remove position whereupon a camming mechanism was actuated to open the plate gripper as it approached the ejection side of the press wherein the expended plate was effectively stripped from the printing cylinder and ejected therefrom. Once the expended plate was removed the operator moved the control handle to the attach position, whereupon a separate camming mechanism was actuated to open the plate gripper as it approached the paper feed side of the press in order to accept the new plate. At this point the operator had to position the new plate up against the rapidly oscillating stop fingers with one hand, at an instant when these fingers were in a raised position, and simultaneously hold the control handle in its attach position with the other hand. Operator difficulties in performing this positioning operation resulted in frequent interruptions in the press operation and for this reason the present invention provides a simplified control system to facilitate plate changes.

Specifically, the improved device is designed to provide an intermediate control handle position, in which the stop fingers remain stationary and in a raised sheet arresting position so that the operator may manually place the new printing plate against the raised fingers preparatory to attaching it to the plate-platen cylinder. Once the plate is positioned, the operator will move the control lever to the attach position whereupon tne stop fingers will 'be moved to a withdrawn position and the feeder rollers will insert the new plate into the open plate gripper. Return of the control handle to the neutral position will cause the press to resume normal operation. The unique advantage of this intermediate control handle position lies in the fact that an operator can now present a new plate to stationary stop fingers, rather than to oscillating stop fingers.

Features and advantages of the invention may be gained from the foregoing and the description of a preferred embodiment of the invention which follows.

In the drawings:

lG. 1 is a side elevation view of a short run printing press showing the control handle and associated linkages of the present invention;

FIG. 2 is a similar view, with parts removed, showing the control handle and associated linkages in position for removal of a printing plate;

FIG. 3 is a similar view, with parts removed, showing the control handle and associated linkages in the intermediate position;

FIG. 4 is a similar view, with parts removed, showing the control handle and associated linkages in position for attaching a printing plate;

FIG. 5 is a fragmentary view showing the position of several parts immediately after .a plate is attached to the cylinder;

FlG. 6 is a side view partly in section and partly in elevation showing the position of the stop fingers when the control handle is positioned for plate removal as in FIG. 2;

FIG. 7 is a view similar to FIG. 4 showing the position of the stop fingers when the control handle is in the intermediate position as in FIG. 3;

HG. 8 is a view similar to FIG. 5 showing the position of the stop fingers when the control handle is positioned for attaching a new plate as in FIG. 4;

FIG. 9 is an oblique face view taken on the line 99 of FlG. 3 looking in the direction of the arrows;

FIG. 10 is an oblique cross-sectional view taken on line lll-lti of FIG. 2; and

FIG. 11 is an oblique cross-sectional View taken on line 11-11 of PEG. 4.

Referring to the drawings, a short run printing press ill is shown in FIG. 1. As usual, a plate-platen cylinder 11 and a blanket cylinder 12 are mounted on the shafts l3 and 14 respectively, both shafts being rotatably journalledadjacent their ends in the side frames 15 of the press 16. The handle 16, projecting through the face plate :19, past the upper edge of side frame 15', is the control member of the present invention. Handle 16 is pivotally mounted on the pin 20 and is provided, near its lower end, with the roller 32 rotatably and eccentrically mounted on stud 21. A tension spring 22, disposed between the lower end of handle 16 and pin 23, which is fastened to the bracket 17, maintains the handle in neutral position when it is not being manually actuated. The spring 22 returns the handle to neutral position as soon as the operator releases it after moving it to any operative position. The intermediate position is determined by lug 18 (FIG. 9) against which handle 16 is held when the operator desires to position a new plate on the cylinder 11, as hereinafter described.

As hereinbefore mentioned, the control handle has three operating positions, remove, intermediate, and attach. The mechanism (see FIG. 2) associated with handle 16 for removing a plate secured to the printing cylinder comprises the lever 24 pivotally mounted on the pin 25 and an adjustable activating rod 26 fixedly mounted on lever 24- and fastened to one arm of the bell crank 38. Lever 24- is notched at '29 on its lower side and is engaged by roller 32 on its upper side. Notch 29 is positioned to engage pin 28 when handle 16 is in plate removing posit-ion (FIG. 2) thereby preventing pin 28 from raising the stripper rollers olf cylinder 11 as the plate segment of the cylinder passes thereunder. This is done so that the stripper rollers which normally do not engage the plate segment of the cylinder may cooperate with a plate being removed from the cylinder to assist in ejecting the plate once its leading edge is released by the gripper mechanism.

The direct end achieved by shifting handle 16 into re moval position is to move one cam 34 into position wherein it will actuate the plate gripper mounted on cylinder 11 as described in copending application Serial No. 712,429, now US. Patent No. 2,990,768. For this reason, cam 34 is provided with two short rods 463* and 41 (FIG. 10) projecting perpendicularly from the frameward side of the cam and slidably passing through two apertures in side frame 15. These short rods are fastened to the flange 42 of the cam block 4 3 by nuts 44 and 45. The compression spring 49, arranged between the side frame and cam block 43 in adjacently aligned wells, maintains cam 34 in a position out of the path of the plate gripper bar follower 36. Cam 34, when in operative position opens the plate gripper for removal of a printing plate as shown in FIG. 10. The gripper bar follower 36 which actuates the plate gripper and a portion of the crank arm 39 of the cam operated gripper rotate in the direction indicated.

When it is desired to move cam 34 to engage follower 36, i.e., when a printing plate fastened to the plate-platen cylinder is to be removed therefrom, handle 16 is shifted to the position shown in FIG. 2, thereby pivoting lever 24 and raising rod 26 as indicated in FIG. 10, whereupon bell crank 30 is pivoted in a counterclockwise direction bringing the free arm of the bell crank, which is normally disposed directly in front of flanged block 43, into contact with the head of this block. The continued counterclockwise movement of the bell crank 39 slides cam 34 into position shown in solid lines, thereby compressing spring 49 and placing cam 34 in the path of follower 36 (FIG. 10).

In a similar manner, when it is desired to attach a new printing plate on cylinder 11, cam 35 is utilized to open the plate gripper on the feed side of the press. The cam is moved into operative position to engage follower 36 by a mechanism similar to that employed in the operation of cam 34 (FIG. 10). Again, this mechanism is actuated by handle 16 and comprises a rod 52 which is formed as shown, and a bell crank 53, pivotally mounted on bracket 55 which is fastened to the side of frame 15. It has been found that rod 52 should be rigid and free from flexure when it is moved by the action of handle 16. The upper end of rod 52 is slidably fastened to handle 16 at a point intermediate its ends by the screw 33 while the lower end is fastened to one arm of the bell crank 53. The other arm of the bell crank presses against the spring biased flange block so that, when actuated, it can slide cam 35 into the path of follower 36 thereby operating the plate gripper mechanism when it passes the feed station of the press.

In two cylinder machines of the type illustrated, bot printing plates and paper sheets are fed into their respective grippers which are located 180 degrees from each other on the plate-platen cylinder of the press by the same feed rollers. The usual stop fingers and feed rollers, which are a part of the feeding mechanism, are normally activated in timed relationship with the appearance of the paper gripper at the feed side of the machine, which is the right side in FIGURES 1, 2, 3 and 4. However, when a printing plate is being fed, the timing of the operation of the stop fingers and feed rollers must be changed by 180 degrees rotation of the printing cylinder 11, in order that they be activated in accordance with the appearance of the plate gripper at the feed side of the machine rather than with the appearance of the sheet gripper as during printing operations on the press.

The timing above referred to is controlled by the cam 64, mounted on the end of plate-platen cylinder shaft 13, and having a dwell 51 on its periphery, the purpose of which will be described hereinafter. The lever 65, pivotally mounted on the pin 66, carries at one end thereof a follower roller 69, which is pivoted into contact with cam 64 by the tension spring 78 extending between lever 65 and side frame 15. it is through cam actuated lever 65 that the timing for periodic feeding of paper sheets to the sheet gripper mechanism is obtained in the following manner.

When sheets are being fed to the press during printing operations, the tension spring 85 disposed between the lever 79 and lever 65 normally maintains the linkages in the paper feed position with the stud 83 provided on lever 65 engaged in notch 31 formed in lever 79. Lever 7% is freely pivoted on pin 35 which is mounted on the arm 75 which in turn pivots on its support 76. To the remote end of arm 75 is pivotally mounted 556 which extends to and is pivotally connected to lever 89. Lever 89 is secured to the end of rock shaft 90 so that as the lever is actuated the rock shaft is oscillated. The rock shaft carries the stop fingers 88 against which sheets of paper or plates are positioned preparatory to being fed to the press (FIG. 6). A spring 73 urges lever 89, and with it shaft 90 and stop fingers 88 to the sheet arresting positions. A lever 93 extending between pin and the crank arm 91, which is mounted on the shaft 92, pivots the arm 91 and shaft 92 when actuated to increase the spring pressure acting on feed rollers 95 during a sheet feeding operation. When the spring pressure is relieved, roller 95 simply rests on a sheet of paper or plate which is positioned against the stop fingers 88.

When paper is automatically being fed into the machine, the control handle 16 is urged by spring 22 into neutral position and lever 79 is urged by spring so that the notch 81 engages stud 83. Now, when follower 69 rides over the dwell 51 on the surface of cam 64 as the paper gripper comes around to the feed side of the machine, lever 65 is caused to pivot counterclockwise, thereby sliding lever 79 to the left as viewed in the drawings. The movement of lever 79 pivots arm 75 counterclockwise, which in turn actuates link 86 and lever 39 to pivot the stop fingers mounted on shaft out of the path of the sheet of paper which had been positioned against the stop fingers. At the same time link 93 pivots the crank arm 91, serving to increase the spring pressure on upper feed roller $5 to thereby drive the sheet into the paper gripper.

When a printing plate is to be fed into the press, handle 16 is moved to its intermediate position (FIG. 3). Roller 32 pivots lever 79 in a counterclockwise direction, thereby disengaging notch 81 from stud 83 and also leaving notch 32 and stud 84 disengaged. Stud 84 is mounted on the lever 71 which is pivoted at 72 and carries a follower 73 which engages cam 64 as does follower 69 of lever 65. Lever 79 is now in the intermediate position wherein it is disengaged from lever 71 and lever 65 which are continually being activated by cam 64. With lever 79 inactive, lever 93 and link 86 will also be inactive, thereby allowing spring 7 S to raise the stop fingers 88 by pivoting member 89. Spring 7 8 is restrained to accurately elevate the stop fingers to a sheet arresting position by the engagement of the eccentric pivot of link 86 with adjustable stop 87. The operator now has an opportunity to manually position the new plate against raised stop fingers which remain in this position even though the printing cylinder continues to rotate. This eliminates the necessity of timing the insertion of the new plate to correspond with the normally oscillating stop fingers and enables the operator to change plates easily.

Once the new plate is located against the stop fingers, handle 16 is moved to the attach position (FIG. 4) thereby engaging notch 52 with stud 84. The stop fingers and feed rollers (FIG. 8) will now be operated as hereinbefore mentioned when roller 73 rides over the dwell 51 on cam 64. In other words, the feed rollers and stop fingers will be operated when the plate gripper rather than the sheet gripper comes around to the feed side of the machine, inasmuch as they are operated by the action of lever 71 rather than by lever 65.

At the time a new plate is attached to the printing press, the mechanism next to be described is also operated. A cam 97 is mounted outside cam 64 on shaft 13 as shown in FIG. 1. Mounted on cam 97 is the roller 99 which actuates a lever 100 by engaging the lower surface thereof upon every counterclockwise revolution of shaft 15. This intermittent actuation of lever 109 causes it to oscillate on the screw 191. The spring 103 mounted between the stud 104 and the screw 192 operates to pivot lever 19% in a clockwise direction whereupon screw 102 is biased against rod 52 with its inward extension thereby restraining the pivotal motion of lever 100 (FIG. 1). Lever 1% is so positioned that its upper end will engage the extension on the latch 19% mounted on rod 52 by screw 110 when handle 16 is in the attach position and roller 99 engages lever lfiil. Latch 106 is provided with the slot 107 which facilitates adjustment thereof. The spring 168 mounted between slot 167 and stud 104 operates to pull rod 52 to the right thereby biasing the left side of the L-shaped slot 109 of rod 52 against the screw 33 (FIG. 1).

During normal operation of the printing press the left side of L-slot 1459 is biased against screw 33 and this position is retained when handle 16 is moved into the attach position wherein it pivots on pin 29 thereby forcing rod 52 down. This downward movement of rod 52 causes cam 35 to move into position whereupon the plate gripper bar follower 36 is actuated and a new plate is accepted in the plate gripper. When the plate gripper passes the feed side of the press 19, roller 99 rotating with shaft 13 engages lever 109. As roller 99 rides over the high point on the lower edge of lever this lever is pivoted counterclockwise whereupon it engages extension 135 on latch 196. Continued counterclockwise movement of lever 100 pulls latch 196 to the left along with rod 52 and L-slot 109 whereupon spring 49 exerting pressure on bell crank 53 raises rod 52 so that screw 33 now biases against the lower face of L-slot 169. Release of hell crank 53 by spring 49 also operates to withdraw cam 35 from the path of the gripper bar roll 36 thereby preventing intermittent opening of the plate gripper as it passes the feed side of press 10 despite the fact that handle 16 may be inadvertently held in the attach position.

A further feature of the present invention operates to eliminate the possibility of moving the control handle into the attach position whenever the plate gripper bar follower 36 is adjacent cam 35 thereby preventing the abrupt engagement of these latter parts. The roller 115 mounted on member 116 rides over the surface of cam 97 (FIG. 5). Member 116 and the lever 117 fixedly connected thereto are pivotally mounted on the stud 113. As roller 115 rides over the depression surface of cam 97, lever 117 is pivoted counterclockwise to engage surface 119 f link 79 (FIG. 5). In this manner lever 117 prevents control handle movement into the attach position because the pivotal motion of handle 16 depresses roller 32 on link 79 is prematurely restrained. Lever 117 is only pivoted counterclockwise into operative position when cam 35 is adjacent the gripper bar roll 36, that is, when roller 115 n'des over the depression surface of cam 97.

A further advantage of this latter mechanism is that the operator cannot move handle 16 into the attach position immediately after the plate gripper has passed the feed side of press 16. This eliminates the possibility of moving handle 16 into attach position only to have it released by the following engagement of roller 99 on lever 1013 thereby requiring another movement of the control handle first to the neutral position and then back into the attach position with the further possibility of a similar re-occurrence.

Assuming that a printing plate, which it is desired to replace, is presently secured on the printing cylinder, this invention operates in the following manner. Handle 16 is shifted into the remove position (FIG. 2) and cam 34 is thereby moved into the path of the plate gripper bar follower 36, in the manner hereinbefore described. When the gripper follower bar strikes cam 34, the plate gripper opens and ejects the expended plate into a delivery basket. The handie 16 is then moved to the intermediate position (FIG. 3) and a new plate is positioned up against the raised stop fingers as above described and then handle 16 is moved to the attach position (FIG. 4) and cam 35 is moved into the path of the gripper bar follower 36, thereby opening the plate gripper at the same time that the stop fingers and feed rollers are activated, resulting in the insertion of a new plate 94 (FIG. 8) into the gripper. Return of the control handle to the neutral position restores the timing of the machine to that normally encountered and sheets are fed to the sheet gripper to be printed.

Having thus described the present invention, it is to be understood that many apparently diiferent embodiments of the invention can be made without departing from the spirit and scope thereof and therefore the description and drawings hereof are to be interpreted in an illustrative rather than in a limiting sense.

What is claimed is:

1. In a printing press having a printing cylinder, 21 plate gripper carried by said cylinder, two slidably mounted cams for operating said gripper and a stop movable into and out of sheet arresting position for regulating the flow of sheets into the machine, the combination of a handle for controlling the attachment of printing plates to said printing cylinder, means operable by said handle when placed in a first position for moving one of said cams into gripper operating position, separate means operable by said handle when placed in a second position for moving the other of said cams into gripper operating position, and separate means operable when said handle is placed in a third or intermediate position for holding the stop fingers in a raised sheet arresting position whereby a printing plate can be manually placed against said fingers preparatory to attachment to the cylinder.

2. In a two cylinder printing press having a printing cylinder, a plate gripper carried by said cylinder, feeder mechanism including a stop finger movable into and out of sheet arresting position for timing the feed of sheets into the press, a first lever for actuating said feeder mechanism to feed sheets to be printed to the press, a second lever for actuating said feeder mechanism to feed printing plates to be attached to said cylinder, a cam for actuating said levers in proper timed relationship to the rotation of the press, a pivoting lever connected to said feeder mechanism, spring means normally urging said pivoting lever into engagement with said first lever, two slidably mounted cams for operating said plate gripper, said cams normally being biased out of gripper operating position, the combination of a handle for controlling the attachment of printing plates to said printing cylinder, means operable by said handle when placed in one posi tion for moving one of said cams into gripper operating position to effect removal of a printing plate, separate means operable by said handle when placed in the second position for moving the other of said cams into gripper operating position to effect attachment of a printing plate to said cylinder and to pivot said pivoting lever out of engagement with said first lever and into engagement with said second lever, and separate means for maintaining the stop finger in a sheet arresting position when said handle is placed in a third or intermediate position wherein the pivoting lever is out of engagement with both said first and said second levers 3. A rotary printing press wherein printing plates are gripped by a plate gripper mounted on the plate cylinder and automatically exchanged while said plate cylinder continues to rotate, said press comprising a cam slidable between a gripper operating and an inoperative position but normally biased to the inoperative position, said cam neing adapted to open and close the plate gripper to effect the attachment of a printing plate to said plate cylinder, means for feeding a printing plate to said printing cylinder including a mechanism having a stop finger movable into and out of a sheet arresting position, means movable between a first position and a plate attach position for controlling the attachment of a printing plate to said cylinder, means operative when said control means is moved to a plate attach position for sliding said cam to a gripper operating position and for actuating said feed mechanism to feed a printing plate to said cylinder, and means operative when said control means is moved to a first position for maintaining said stop finger in a sheet arresting position whereby a printing plate can be (I placed against a stationary stop finger before the control means is operated to attach the printing plate to the printing cylinder 4. A rotary printin press according to claim 3 including spring means for biasing the stop finger into the sheet arresting position, a timing cam mounted on the printing cylinder shaft, and a lever mechanism to move said stop finger to a retracted position so that a printing plate can be fed to the plate grippers.

5. A rotary printing press according to claim 4 wherein the lever mechanism includes a lever pivotally mounted on the machine frame for periodic reciprocation by said timing cam, a rocker member pivotally mounted for movement into and out of engagement with said lever by the aforesaid control means, the rocker member being in engagement with said lever for reciprocation therewith when said control means is moved to a plate attach position and out of engagement with said control means is in the first position, and a link connecting said rocker member to said stop finger mechanism so that the stop finger is moved to a retracted position when the control means is moved to a plate attach position.

6. A rotary printing press according to claim 5 wherein the feed mechanism includes an upper feed roll assembly and a link connecting said rocker mechanism to said assembly so that the upper feed roll assembly is actuated to engage a printing plate positioned against the stop finger when the control means is moved to a plate attach position.

7. A rotary printing press wherein printing plates are gripped by a plate gripper mounted on the plate cylinder and automatically exchanged While said plate cylinder continues to rotate, said press comprising a cam slidable between a gripper operating position and an inoperative position, biasing means for normally maintaining said cam in an inoperative position, means movable to a plate attach position for controlling the attachment of a printing plate to said cylinder linkage means connected to said control means and operative for sliding said cam to a gripper operating position when said control means is moved to a plate attach position, a cam carried by the printing cylinder shaft, a lever actuated by said last named cam, and means connecting said lever and said linkage means to restore said linkage means to a nonoperative position even though said control means is maintained in a plate attach position whereby said slidable cam is restored to an inoperative position.

8. A rotary printing press according to claim 7 wherein the means for connecting the linkage means to the control means comprises an L-shaped slot on said linkage means and a pin co-acting therewith on said control means.

9. A rotary printing press according to claim 7 including means for preventing movement of the control means to a plate attach position when the follower of the plate gripper is opposite the slidable cam.

References Cited in the file of this patent UNITED STATES PATENTS 2,482,408 Ford Sept. 20, 1949 2,459,416 George et al. Aug. 21, 1956 2,990,768 Fischetti July 4, 1961 FOREIGN PATENTS 747,002 Great Britain Mar. 21, 1956 

1. IN A PRINTING PRESS HAVING A PRINTING CYLINDER, A PLATE GRIPPER CARRIED BY SAID CYLINDER, TWO SLIDABLY MOUNTED CAMS FOR OPERATING SAID GRIPPER AND A STOP MOVABLE INTO AND OUT OF SHEET ARRESTING POSITION FOR REGULATING THE FLOW OF SHEETS INTO THE MACHINE, THE COMBINATION OF A HANDLE FOR CONTROLLING THE ATTACHMENT OF PRINTING PLATES TO SAID PRINTING CYLINDER, MEANS OPERABLE BY SAID HANDLE WHEN PLACED IN A FIRST POSITION FOR MOVING ONE OF SAID CAMS INTO GRIPPER OPERATING POSITION, SEPARATE MEANS OPERABLE BY SAID HANDLE WHEN PLACED IN A SECOND POSITION FOR MOVING THE OTHER OF SAID CAMS INTO GRIPPER OPERATING POSITION, AND SEPARATE MEANS OPERABLE WHEN SAID HANDLE IS PLACED IN A THIRD OR INTERMEDIATE POSITION FOR HOLDING THE STOP FINGERS IN A RAISED SHEET ARRESTING POSITION WHEREBY A 